Clamp for securing an object to a structure

Abstract

Apparatus and methods provide an electrically isolating clamp that is suitable for use, among other locations, within a composite wing structure and other fuel environments. According to embodiments described herein, the clamp includes a clamp body and cushion. The clamp body is manufactured from a non-conductive material and includes a strap and a base. The cushion may be manufactured from a different non-conductive material to provide at least two layers of electrical isolation between the tube or other object being secured and a structure. The cushion material allows for axial movement of the tube through the cushion. The cushion is disposed between the strap and the base. Shoulder flanges prevent axial movement of the cushion with respect to the clamp body. The clamp may have a cushion retention mechanism to secure the cushion within the strap prior to installation around the tube.

1. A clamp for securing an object to a structure, comprising:
 a clamp body configured for attachment to the structure, the clamp body comprising a strap and a base, wherein the strap and the base are configured to mate together and define a cushion retaining recess, and wherein the strap comprises two strap flanges, each with a strap aperture, and the base comprises two base flanges, each with a base aperture aligned with a strap aperture when the base is mated to the strap; 
 a cushion sized to surround the object and abut an inner surface of the cushion retaining recess, the cushion comprising a rigid upper cushion segment, a rigid lower cushion segment, and a hinge mechanism connecting the rigid upper cushion segment and the rigid lower cushion segment and operative to allow the rigid lower cushion segment to rotate around the hinge mechanism when the rigid upper cushion segment is stationary; 
 a front shoulder flange; and 
 a rear shoulder flange, wherein the front shoulder flange and the rear shoulder flange are configured to limit axial movement of the cushion with respect to the clamp body. 
 
   
   
     2. The clamp of  claim 1 , wherein the base comprises an arcuate cushion support configured to engage the rigid lower cushion segment of the cushion. 
   
   
     3. The clamp of  claim 1 , wherein the cushion retaining recess comprises a front cushion engagement rim and a rear cushion engagement rim, wherein the front shoulder flange is positioned around a circumference of a front edge of the cushion and configured to overlay the front cushion engagement rim, and wherein the rear shoulder flange is positioned around a circumference of a rear edge of the cushion and configured to overlay the rear cushion engagement rim. 
   
   
     4. The clamp of  claim 1 , further comprising a cushion retention mechanism operative to secure the cushion within the strap when the strap is not mated to the base. 
   
   
     5. The clamp of  claim 4 , wherein the cushion retention mechanism comprises a plurality of cushion retention tabs on the rigid upper cushion segment positioned to engage a plurality of cushion retention slots within the cushion retaining recess to secure the cushion to the strap. 
   
   
     6. The clamp of  claim 1 , wherein the clamp body is manufactured from a first non-conductive material, wherein the cushion is manufactured from a second non-conductive material that is not identical to the first non-conductive material such that the clamp provides two layers of electrically isolating material around the object. 
   
   
     7. The clamp of  claim 6 , wherein the first non-conductive material comprises a thermo set and the second non-conductive material comprises a thermoplastic. 
   
   
     8. The clamp of  claim 7 , wherein the thermo set comprises a compression molded thermo set material. 
   
   
     9. The clamp of  claim 8 , wherein the thermoplastic comprises an injection molded thermoplastic material. 
   
   
     10. A method for reducing spark potential associated with a clamp for securing a tube to a fuel tank, comprising:
 removing a metallic clamp from a location inside the fuel tank; 
 installing a cushion within a strap component of a clamp body such that the cushion is secured within the strap component, the clamp body comprising a first electrically isolating material and the cushion comprising a second electrically isolating material; 
 after installing the cushion within the strap component of the clamp body, sliding the strap component and cushion over the tube such that the tube enters an upper cushion segment of the cushion and rotating a lower cushion segment of the cushion around a hinge between the upper cushion segment and the lower cushion segment until the lower cushion segment abuts the tube; and 
 securing the strap component of the clamp body to the fuel tank via a base component of the clamp body with a fastener at the location inside the fuel tank where the metallic clamp was removed, wherein the base component of the clamp body is positioned between the strap component of the clamp body and the fuel tank such that the first electrically isolating material and the second electrically isolating material are disposed between the tube and the fuel tank and between the tube and the fastener. 
 
   
   
     11. The method of  claim 10 , wherein securing the strap component of the clamp body to the fuel tank via the base component of the clamp body with the fastener comprises:
 positioning the base component in place against the fuel tank; 
 positioning the strap component with the cushion and tube against the base component such that a strap aperture of the strap component aligns with a corresponding base aperture of the base component; and 
 installing the fastener through the strap aperture, through the base aperture, and into the fuel tank. 
 
   
   
     12. A clamp assembly for securing an object to a structure, comprising:
 a clamp body manufactured from a first non-conductive material that provides a first insulating material between the object and a fastener used to secure the clamp body to the structure, the clamp body comprising
 a strap comprising two strap legs and a bridge spanning the two strap legs to create a cushion retaining recess in an underside of the strap, the cushion retaining recess comprising a front cushion engagement rim and a rear cushion engagement rim, and 
 a base comprising an arcuate cushion support and two ends, the two ends configured to mate with the two strap legs of the strap on a top side of the base and configured to mate with the structure on an underside of the base; 
 
 a cushion manufactured from a second non-conductive material that allows axial movement of the object within the cushion and provides a second electrically isolating material between the object and the fastener, wherein the cushion is sized to surround the object and abut an inner surface of the cushion retaining recess and comprises
 a front integral shoulder flange positioned around a circumference of a front edge of the cushion and configured to overlay the front cushion engagement rim, a rear integral shoulder flange positioned around a circumference of a rear edge of the cushion and configured to overlay the rear cushion engagement rim such that the front integral shoulder flange and the rear integral shoulder flange limit axial movement of the cushion with respect to the clamp body, 
 an upper cushion segment, 
 a lower cushion segment, and 
 a hinge mechanism connecting the upper cushion segment and the lower cushion segment and operative to allow the lower cushion segment to rotate around the hinge mechanism when the upper cushion segment is stationary, 
 
 wherein the arcuate cushion support of the base is configured to engage the lower cushion segment of the cushion between the front integral shoulder flange and the rear integral shoulder flange; and 
 a cushion retention mechanism operative to secure the cushion within the strap when the strap is not mated to the base. 
 
   
   
     13. A method for reducing spark potential associated with a clamp for securing an object to a structure, comprising:
 aligning a cushion with a cushion retaining recess of a strap component of a clamp body such that a front integral shoulder flange of the cushion overlays a front cushion engagement rim of the strap component and a rear integral shoulder flange of the cushion overlays a rear cushion engagement rim of the strap component; 
 pressing the cushion into the cushion retaining recess of the strap component until a plurality of cushion retention tabs disposed on an outer surface of the cushion engages a plurality of cushion retention slots on an inner surface of the cushion retaining recess to secure the cushion to the strap component; 
 installing the cushion around the object; and 
 securing the strap component of the clamp body to the structure via a base component of the clamp body with a fastener, wherein the base component of the clamp body is positioned between the strap component of the clamp body and the structure such that a first electrically isolating material of the clamp body and a second electrically isolating material of the cushion are disposed between the object and the structure and between the object and the fastener. 
 
   
   
     14. A method for reducing spark potential associated with a clamp for securing an object to a structure, comprising:
 aligning a cushion with a cushion retaining recess of a strap component of a clamp body such that a front integral shoulder flange of the cushion overlays a front cushion engagement rim of the strap component and a rear integral shoulder flange of the cushion overlays a rear cushion engagement rim of the strap component; 
 pressing the cushion into the cushion retaining recess of the strap component until a cushion retention mechanism engages to secure the cushion to the strap component such that the cushion is secured within the strap component, wherein the clamp body comprises a first electrically isolating material and the cushion comprises a second electrically isolating material; 
 after installing the cushion within the strap component of the clamp body, sliding the strap component and cushion over the object such that the object enters an upper cushion segment of the cushion and rotating a lower cushion segment of the cushion around a hinge between the upper cushion segment and the lower cushion segment until the lower cushion segment abuts the object; and 
 securing the strap component of the clamp body to the structure via a base component of the clamp body with a fastener, wherein the base component of the clamp body is positioned between the strap component of the clamp body and the structure such that the first electrically isolating material and the second electrically isolating material are disposed between the object and the structure and between the object and the fastener. 
 
   
   
     15. The method of  claim 14 , wherein the cushion retention mechanism comprises a plurality of cushion retention tabs disposed on an outer surface of the cushion and positioned to engage a plurality of cushion retention slots on an inner surface of the cushion retaining aperture of the strap component of the clamp body. 
   
   
     16. The method of  claim 14 , wherein securing the strap component of the clamp body to the structure via the base component of the clamp body with the fastener comprises:
 positioning the base component in place against the structure; 
 positioning the strap component with the cushion and object against the base component such that a strap aperture of the strap component aligns with a corresponding base aperture of the base component; and 
 installing the fastener through the strap aperture, through the base aperture, and into the structure.